Effect of paleosalinity and maturity on the distribution of dimethyl-MTTCs

摘要

The effect of paleosalinity and thermal maturity on the distribution of dimethyl-MTTCs in sediments is still uncertain. Here, we have studied the relative abundance of dimethyl-MTTCs (beta- and gamma-MTTC) and beta/gamma-MTTC ratio in the 154 lacustrine source rocks. Our results show that thermal maturity has no significant effect on (beta + gamma)-MTTC% and beta/gamma-MTTC ratio in immature and low mature source rocks. The beta/gamma-MTTC ratio may not be used as a maturity parameter. The variation in (beta + gamma)- MTTC% seems to be linked to the depositional environment, especially the paleosalinity. However the depositional conditions do not appear to affect the variation in beta/gamma-MTTC ratio.